1. Field of the Invention
This invention pertains to safety equipment, and more particularly to apparatus for enhancing the safety of persons using filing cabinets.
2. Description of the Prior Art
Multi-drawer filing cabinets are well known. A commonly recognized danger with conventional filing cabinets is that heavily loaded drawers tend to tip the cabinet onto a person opening the drawers.
To reduce the likelihood of a loaded cabinet tipping when opened, various types of interlock mechanisms have been developed. The primary purpose of the interlocks is to prevent more than one drawer from being opened at a time. However, prior interlock devices suffer from certain disadvantages. For example, the cabinets disclosed in U.S. Pat. Nos. 3,404,929; 3,883,200; and 3,888,558 permit opening more than one drawer if the drawers are opened simultaneously. Certain other interlocks are capable of being easily overridden, thereby defeating their purpose. The cabinets disclosed in U.S. Pat. Nos. 4,240,685; 4,272,138; and 4,441,767 utilize vertically reciprocating lift bars in combination with rollers, springs, or lock dogs. The multiplicity of parts renders the cabinet interlocks of the three foregoing patents undesirably expensive and prone to malfunction.
The blocking device of U.S. Pat. No. 4,480,883 employs multi-piece fork shaped cam elements that are not positively restrained in place when a cabinet drawer is opened. Rather, opening a drawer raises the cam elements to unrestrained and unstable positions. Accidental jarring of an open cabinet can cause the cam elements to fall to a stable position, and a second drawer can then be opened. In addition, an accidentally displaced cam element prevents the associated drawer from being closed without damaging the cam element or other components.
Thus, a need exists for an improved mechanism for controlling the opening of filing cabinet drawers.